Add age verification on sign-up (#34150)

app/controllers/api/v1/accounts_controller.rb

@@ -119,7 +119,7 @@ class Api::V1::AccountsController < Api::BaseController
   end
 
   def account_params
-    params.permit(:username, :email, :password, :agreement, :locale, :reason, :time_zone, :invite_code)
+    params.permit(:username, :email, :password, :agreement, :locale, :reason, :time_zone, :invite_code, :date_of_birth)
   end
 
   def invite

app/controllers/auth/registrations_controller.rb

@@ -62,7 +62,7 @@ class Auth::RegistrationsController < Devise::RegistrationsController
 
   def configure_sign_up_params
     devise_parameter_sanitizer.permit(:sign_up) do |user_params|
-      user_params.permit({ account_attributes: [:username, :display_name], invite_request_attributes: [:text] }, :email, :password, :password_confirmation, :invite_code, :agreement, :website, :confirm_password)
+      user_params.permit({ account_attributes: [:username, :display_name], invite_request_attributes: [:text] }, :email, :password, :password_confirmation, :invite_code, :agreement, :website, :confirm_password, :date_of_birth)
     end
   end
 

app/inputs/date_of_birth_input.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class DateOfBirthInput < SimpleForm::Inputs::Base
+  OPTIONS = [
+    { autocomplete: 'bday-day', maxlength: 2, pattern: '[0-9]+', placeholder: 'DD' }.freeze,
+    { autocomplete: 'bday-month', maxlength: 2, pattern: '[0-9]+', placeholder: 'MM' }.freeze,
+    { autocomplete: 'bday-year', maxlength: 4, pattern: '[0-9]+', placeholder: 'YYYY' }.freeze,
+  ].freeze
+
+  def input(wrapper_options = nil)
+    merged_input_options = merge_wrapper_options(input_html_options, wrapper_options)
+    merged_input_options[:inputmode] = 'numeric'
+
+    values = (object.public_send(attribute_name) || '').split('.')
+
+    safe_join(Array.new(3) do |index|
+      options = merged_input_options.merge(OPTIONS[index]).merge id: generate_id(index), 'aria-label': I18n.t("simple_form.labels.user.date_of_birth_#{index + 1}i"), value: values[index]
+      @builder.text_field("#{attribute_name}(#{index + 1}i)", options)
+    end)
+  end
+
+  def label_target
+    "#{attribute_name}_1i"
+  end
+
+  private
+
+  def generate_id(index)
+    "#{object_name}_#{attribute_name}_#{index + 1}i"
+  end
+end

app/javascript/styles/mastodon/forms.scss

@@ -353,6 +353,22 @@ code {
     }
   }
 
+  .input.date_of_birth .label_input {
+    display: flex;
+    gap: 8px;
+    align-items: center;
+
+    input {
+      box-sizing: content-box;
+      width: 32px;
+      flex: 0;
+
+      &:last-child {
+        width: 64px;
+      }
+    }
+  }
+
   .input.select.select--languages {
     min-width: 32ch;
   }

app/models/form/admin_settings.rb

@@ -39,12 +39,14 @@ class Form::AdminSettings
     authorized_fetch
     app_icon
     favicon
+    min_age
   ).freeze
 
   INTEGER_KEYS = %i(
     media_cache_retention_period
     content_cache_retention_period
     backups_retention_period
+    min_age
   ).freeze
 
   BOOLEAN_KEYS = %i(
@@ -88,6 +90,7 @@ class Form::AdminSettings
   validates :show_domain_blocks, inclusion: { in: %w(disabled users all) }, if: -> { defined?(@show_domain_blocks) }
   validates :show_domain_blocks_rationale, inclusion: { in: %w(disabled users all) }, if: -> { defined?(@show_domain_blocks_rationale) }
   validates :media_cache_retention_period, :content_cache_retention_period, :backups_retention_period, numericality: { only_integer: true }, allow_blank: true, if: -> { defined?(@media_cache_retention_period) || defined?(@content_cache_retention_period) || defined?(@backups_retention_period) }
+  validates :min_age, numericality: { only_integer: true }, allow_blank: true, if: -> { defined?(@min_age) }
   validates :site_short_description, length: { maximum: DESCRIPTION_LIMIT }, if: -> { defined?(@site_short_description) }
   validates :status_page_url, url: true, allow_blank: true
   validate :validate_site_uploads

app/models/user.rb

@@ -5,41 +5,42 @@
 # Table name: users
 #
 #  id                        :bigint(8)        not null, primary key
-#  email                     :string           default(""), not null
-#  created_at                :datetime         not null
-#  updated_at                :datetime         not null
-#  encrypted_password        :string           default(""), not null
-#  reset_password_token      :string
-#  reset_password_sent_at    :datetime
-#  sign_in_count             :integer          default(0), not null
-#  current_sign_in_at        :datetime
-#  last_sign_in_at           :datetime
+#  age_verified_at           :datetime
+#  approved                  :boolean          default(TRUE), not null
+#  chosen_languages          :string           is an Array
+#  confirmation_sent_at      :datetime
 #  confirmation_token        :string
 #  confirmed_at              :datetime
-#  confirmation_sent_at      :datetime
-#  unconfirmed_email         :string
-#  locale                    :string
+#  consumed_timestep         :integer
+#  current_sign_in_at        :datetime
+#  disabled                  :boolean          default(FALSE), not null
+#  email                     :string           default(""), not null
 #  encrypted_otp_secret      :string
 #  encrypted_otp_secret_iv   :string
 #  encrypted_otp_secret_salt :string
-#  consumed_timestep         :integer
-#  otp_required_for_login    :boolean          default(FALSE), not null
+#  encrypted_password        :string           default(""), not null
 #  last_emailed_at           :datetime
+#  last_sign_in_at           :datetime
+#  locale                    :string
 #  otp_backup_codes          :string           is an Array
-#  account_id                :bigint(8)        not null
-#  disabled                  :boolean          default(FALSE), not null
-#  invite_id                 :bigint(8)
-#  chosen_languages          :string           is an Array
-#  created_by_application_id :bigint(8)
-#  approved                  :boolean          default(TRUE), not null
+#  otp_required_for_login    :boolean          default(FALSE), not null
+#  otp_secret                :string
+#  reset_password_sent_at    :datetime
+#  reset_password_token      :string
+#  settings                  :text
+#  sign_in_count             :integer          default(0), not null
 #  sign_in_token             :string
 #  sign_in_token_sent_at     :datetime
-#  webauthn_id               :string
 #  sign_up_ip                :inet
-#  role_id                   :bigint(8)
-#  settings                  :text
 #  time_zone                 :string
-#  otp_secret                :string
+#  unconfirmed_email         :string
+#  created_at                :datetime         not null
+#  updated_at                :datetime         not null
+#  account_id                :bigint(8)        not null
+#  created_by_application_id :bigint(8)
+#  invite_id                 :bigint(8)
+#  role_id                   :bigint(8)
+#  webauthn_id               :string
 #
 
 class User < ApplicationRecord
@@ -111,6 +112,7 @@ class User < ApplicationRecord
   validates_with RegistrationFormTimeValidator, on: :create
   validates :website, absence: true, on: :create
   validates :confirm_password, absence: true, on: :create
+  validates :date_of_birth, presence: true, date_of_birth: true, on: :create, if: -> { Setting.min_age.present? }
   validate :validate_role_elevation
 
   scope :account_not_suspended, -> { joins(:account).merge(Account.without_suspended) }
@@ -129,6 +131,7 @@ class User < ApplicationRecord
 
   before_validation :sanitize_role
   before_create :set_approved
+  before_create :set_age_verified_at
   after_commit :send_pending_devise_notifications
   after_create_commit :trigger_webhooks
 
@@ -140,7 +143,7 @@ class User < ApplicationRecord
 
   delegate :can?, to: :role
 
-  attr_reader :invite_code
+  attr_reader :invite_code, :date_of_birth
   attr_writer :external, :bypass_invite_request_check, :current_account
 
   def self.those_who_can(*any_of_privileges)
@@ -157,6 +160,17 @@ class User < ApplicationRecord
     Rails.env.local?
   end
 
+  def date_of_birth=(hash_or_string)
+    @date_of_birth = begin
+      if hash_or_string.is_a?(Hash)
+        day, month, year = hash_or_string.values_at(1, 2, 3)
+        "#{day}.#{month}.#{year}"
+      else
+        hash_or_string
+      end
+    end
+  end
+
   def role
     if role_id.nil?
       UserRole.everyone
@@ -432,6 +446,10 @@ class User < ApplicationRecord
     end
   end
 
+  def set_age_verified_at
+    self.age_verified_at = Time.now.utc if Setting.min_age.present?
+  end
+
   def grant_approval_on_confirmation?
     # Re-check approval on confirmation if the server has switched to open registrations
     open_registrations? && !sign_up_from_ip_requires_approval? && !sign_up_email_requires_approval?

app/serializers/rest/instance_serializer.rb

@@ -107,6 +107,7 @@ class REST::InstanceSerializer < ActiveModel::Serializer
       enabled: registrations_enabled?,
       approval_required: Setting.registrations_mode == 'approved',
       message: registrations_enabled? ? nil : registrations_message,
+      min_age: Setting.min_age.presence,
       url: ENV.fetch('SSO_ACCOUNT_SIGN_UP', nil),
     }
   end

app/services/app_sign_up_service.rb

@@ -41,7 +41,7 @@ class AppSignUpService < BaseService
   end
 
   def user_params
-    @params.slice(:email, :password, :agreement, :locale, :time_zone, :invite_code)
+    @params.slice(:email, :password, :agreement, :locale, :time_zone, :invite_code, :date_of_birth)
   end
 
   def account_params

app/validators/date_of_birth_validator.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class DateOfBirthValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    record.errors.add(attribute, :below_limit) if value.present? && value.to_date > min_age.ago
+  rescue Date::Error
+    record.errors.add(attribute, :invalid)
+  end
+
+  private
+
+  def min_age
+    Setting.min_age.to_i.years
+  end
+end

app/views/admin/settings/registrations/show.html.haml

@@ -12,6 +12,9 @@
 
   .flash-message= t('admin.settings.registrations.moderation_recommandation')
 
+  .fields-group
+    = f.input :min_age, as: :string, wrapper: :with_block_label, input_html: { inputmode: 'numeric' }
+
   .fields-row
     .fields-row__column.fields-row__column-6.fields-group
       = f.input :registrations_mode,

app/views/auth/registrations/new.html.haml

@@ -21,20 +21,19 @@
     = f.simple_fields_for :account do |ff|
       = ff.input :username,
                  append: "@#{site_hostname}",
-                 input_html: { 'aria-label': t('simple_form.labels.defaults.username'), autocomplete: 'off', placeholder: t('simple_form.labels.defaults.username'), pattern: '[a-zA-Z0-9_]+', maxlength: Account::USERNAME_LENGTH_LIMIT },
-                 label: false,
+                 input_html: { autocomplete: 'off', pattern: '[a-zA-Z0-9_]+', maxlength: Account::USERNAME_LENGTH_LIMIT, placeholder: ' ' },
                  required: true,
                  wrapper: :with_label
     = f.input :email,
               hint: false,
-              input_html: { 'aria-label': t('simple_form.labels.defaults.email'), autocomplete: 'username' },
-              placeholder: t('simple_form.labels.defaults.email'),
-              required: true
+              input_html: { autocomplete: 'username', placeholder: ' ' },
+              required: true,
+              wrapper: :with_label
     = f.input :password,
               hint: false,
-              input_html: { 'aria-label': t('simple_form.labels.defaults.password'), autocomplete: 'new-password', minlength: User.password_length.first, maxlength: User.password_length.last },
-              placeholder: t('simple_form.labels.defaults.password'),
-              required: true
+              input_html: { autocomplete: 'new-password', minlength: User.password_length.first, maxlength: User.password_length.last, placeholder: ' ' },
+              required: true,
+              wrapper: :with_label
     = f.input :password_confirmation,
               hint: false,
               input_html: { 'aria-label': t('simple_form.labels.defaults.confirm_password'), autocomplete: 'new-password', maxlength: User.password_length.last },
@@ -53,6 +52,14 @@
               required: false,
               wrapper: :with_label
 
+  - if Setting.min_age.present?
+    .fields-group
+      = f.input :date_of_birth,
+                as: :date_of_birth,
+                hint: t('simple_form.hints.user.date_of_birth', age: Setting.min_age.to_i),
+                required: true,
+                wrapper: :with_block_label
+
   - if approved_registrations? && @invite.blank?
     %p.lead= t('auth.sign_up.manual_review', domain: site_hostname)
 

config/locales/activerecord.en.yml

@@ -55,6 +55,8 @@ en:
               too_soon: is too soon, must be later than %{date}
         user:
           attributes:
+            date_of_birth:
+              below_limit: is below the age limit
             email:
               blocked: uses a disallowed e-mail provider
               unreachable: does not seem to exist

config/locales/simple_form.en.yml

@@ -88,6 +88,7 @@ en:
         favicon: WEBP, PNG, GIF or JPG. Overrides the default Mastodon favicon with a custom icon.
         mascot: Overrides the illustration in the advanced web interface.
         media_cache_retention_period: Media files from posts made by remote users are cached on your server. When set to a positive value, media will be deleted after the specified number of days. If the media data is requested after it is deleted, it will be re-downloaded, if the source content is still available. Due to restrictions on how often link preview cards poll third-party sites, it is recommended to set this value to at least 14 days, or link preview cards will not be updated on demand before that time.
+        min_age: Users will be asked to confirm their date of birth during sign-up
         peers_api_enabled: A list of domain names this server has encountered in the fediverse. No data is included here about whether you federate with a given server, just that your server knows about it. This is used by services that collect statistics on federation in a general sense.
         profile_directory: The profile directory lists all users who have opted-in to be discoverable.
         require_invite_text: When sign-ups require manual approval, make the “Why do you want to join?” text input mandatory rather than optional
@@ -146,6 +147,7 @@ en:
         min_age: Should not be below the minimum age required by the laws of your jurisdiction.
       user:
         chosen_languages: When checked, only posts in selected languages will be displayed in public timelines
+        date_of_birth: We have to make sure you're at least %{age} to use Mastodon. We won't store this.
         role: The role controls which permissions the user has.
       user_role:
         color: Color to be used for the role throughout the UI, as RGB in hex format
@@ -271,6 +273,7 @@ en:
         favicon: Favicon
         mascot: Custom mascot (legacy)
         media_cache_retention_period: Media cache retention period
+        min_age: Minimum age requirement
         peers_api_enabled: Publish list of discovered servers in the API
         profile_directory: Enable profile directory
         registrations_mode: Who can sign-up
@@ -349,6 +352,9 @@ en:
         jurisdiction: Legal jurisdiction
         min_age: Minimum age
       user:
+        date_of_birth_1i: Day
+        date_of_birth_2i: Month
+        date_of_birth_3i: Year
         role: Role
         time_zone: Time zone
       user_role:

db/migrate/20250313123400_add_age_verified_at_to_users.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddAgeVerifiedAtToUsers < ActiveRecord::Migration[8.0]
+  def change
+    add_column :users, :age_verified_at, :datetime
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_03_05_074104) do
+ActiveRecord::Schema[8.0].define(version: 2025_03_13_123400) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
 
@@ -1188,6 +1188,7 @@ ActiveRecord::Schema[8.0].define(version: 2025_03_05_074104) do
     t.text "settings"
     t.string "time_zone"
     t.string "otp_secret"
+    t.datetime "age_verified_at"
     t.index ["account_id"], name: "index_users_on_account_id"
     t.index ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true
     t.index ["created_by_application_id"], name: "index_users_on_created_by_application_id", where: "(created_by_application_id IS NOT NULL)"

spec/controllers/auth/registrations_controller_spec.rb

@@ -342,6 +342,42 @@ RSpec.describe Auth::RegistrationsController do
       end
     end
 
+    context 'when age verification is enabled' do
+      subject { post :create, params: { user: { account_attributes: { username: 'test' }, email: 'test@example.com', password: '12345678', password_confirmation: '12345678', agreement: 'true' }.merge(date_of_birth) } }
+
+      before do
+        Setting.min_age = 16
+      end
+
+      let(:date_of_birth) { {} }
+
+      context 'when date of birth is below age limit' do
+        let(:date_of_birth) { 13.years.ago.then { |date| { 'date_of_birth(1i)': date.day.to_s, 'date_of_birth(2i)': date.month.to_s, 'date_of_birth(3i)': date.year.to_s } } }
+
+        it 'does not create user' do
+          subject
+          user = User.find_by(email: 'test@example.com')
+          expect(user).to be_nil
+        end
+      end
+
+      context 'when date of birth is above age limit' do
+        let(:date_of_birth) { 17.years.ago.then { |date| { 'date_of_birth(1i)': date.day.to_s, 'date_of_birth(2i)': date.month.to_s, 'date_of_birth(3i)': date.year.to_s } } }
+
+        it 'redirects to setup and creates user' do
+          subject
+
+          expect(response).to redirect_to auth_setup_path
+
+          expect(User.find_by(email: 'test@example.com'))
+            .to be_present
+            .and have_attributes(
+              age_verified_at: not_eq(nil)
+            )
+        end
+      end
+    end
+
     include_examples 'checks for enabled registrations', :create
   end
 

spec/requests/api/v1/accounts_spec.rb

@@ -74,12 +74,45 @@ RSpec.describe '/api/v1/accounts' do
 
   describe 'POST /api/v1/accounts' do
     subject do
-      post '/api/v1/accounts', headers: headers, params: { username: 'test', password: '12345678', email: 'hello@world.tld', agreement: agreement }
+      post '/api/v1/accounts', headers: headers, params: { username: 'test', password: '12345678', email: 'hello@world.tld', agreement: agreement, date_of_birth: date_of_birth }
     end
 
     let(:client_app) { Fabricate(:application) }
     let(:token) { Doorkeeper::AccessToken.find_or_create_for(application: client_app, resource_owner: nil, scopes: 'read write', use_refresh_token: false) }
     let(:agreement) { nil }
+    let(:date_of_birth) { nil }
+
+    context 'when age verification is enabled' do
+      before do
+        Setting.min_age = 16
+      end
+
+      let(:agreement) { 'true' }
+
+      context 'when date of birth is below age limit' do
+        let(:date_of_birth) { 13.years.ago.strftime('%d.%m.%Y') }
+
+        it 'returns http unprocessable entity' do
+          subject
+
+          expect(response).to have_http_status(422)
+          expect(response.content_type)
+            .to start_with('application/json')
+        end
+      end
+
+      context 'when date of birth is over age limit' do
+        let(:date_of_birth) { 17.years.ago.strftime('%d.%m.%Y') }
+
+        it 'creates a user', :aggregate_failures do
+          subject
+
+          expect(response).to have_http_status(200)
+          expect(response.content_type)
+            .to start_with('application/json')
+        end
+      end
+    end
 
     context 'when given truthy agreement' do
       let(:agreement) { 'true' }

spec/validators/date_of_birth_validator_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe DateOfBirthValidator do
+  let(:record_class) do
+    Class.new do
+      include ActiveModel::Validations
+
+      attr_accessor :date_of_birth
+
+      validates :date_of_birth, date_of_birth: true
+    end
+  end
+
+  let(:record) { record_class.new }
+
+  before do
+    Setting.min_age = 16
+  end
+
+  describe '#validate_each' do
+    context 'with an invalid date' do
+      it 'adds errors' do
+        record.date_of_birth = '76.830.10'
+
+        expect(record).to_not be_valid
+        expect(record.errors.first.attribute).to eq(:date_of_birth)
+        expect(record.errors.first.type).to eq(:invalid)
+      end
+    end
+
+    context 'with a date below age limit' do
+      it 'adds errors' do
+        record.date_of_birth = 13.years.ago.strftime('%d.%m.%Y')
+
+        expect(record).to_not be_valid
+        expect(record.errors.first.attribute).to eq(:date_of_birth)
+        expect(record.errors.first.type).to eq(:below_limit)
+      end
+    end
+
+    context 'with a date above age limit' do
+      it 'does not add errors' do
+        record.date_of_birth = 16.years.ago.strftime('%d.%m.%Y')
+
+        expect(record).to be_valid
+      end
+    end
+  end
+end